Wicket produce bags have been developed for automatic produce packing machines. One portion of the bag has holes formed in it so that the bags can be suspended from wickets or pegs on an automatic packing machine. The earliest such bags were of polyethylene film.
Produce bags formed of a synthetic resin fabric mesh have been recently developed by the assignee of the present application, for example as described in co-pending U. S. patent application Ser. No. 08/888,175, filed Jul. 3, 1997. These bags were formed of a synthetic resin fabric mesh, such as the woven fabric of cross-laminated synthetic resin fibers known as Cross Laminated Airy Fabric or (CLAF) from Amoco Fabrics & Fibers, Inc. This fabric is an open mesh material of cross-laminated warp and weft strands or fibers of synthetic resin.
These types of bags are particularly useful for produce that must have access to fresh air to preserve the shelf life of the produce. However, when wicket holes are formed in this type of fabric mesh for automatic produce bag filling or packing machine purposes, problems have been found to occur. Slits were formed in the mesh in the area of the wicket holes leading away from the holes. The slits were formed in order to aid in tearing of the bag away from the packing machine once the bag was filled with product.
When the fabric mesh was slit for this purpose near the wicket holes, only a certain number of synthetic resin fiber strands in the fiber mesh were left uncut. The remaining uncut fiber strands were the sole support for the bag when it was suspended from the wicket rods or pegs and being filled with product. The number of strands left uncut was variable and indeterminate, and the reliability of the bags for use in automatic packing machines suffered. Bags with too many strands cut did not have adequate strength for use and would fall from the wickets during filling operations. Faulty bags could slow up operation of automatic packing machines by falling from the wickets when being filled with produce.
Composite bags formed of one synthetic resin mesh sheet and one synthetic resin film sheet have been proposed. So far as is known, however, the two sheets have been joined together along a common inner seam formed between the two walls at a bag bottom on or near the bottom portions of the sheets. The common inner seam was thus located to form the bottom of the contents holding portion of the bag. However, with this structure, problems have arisen, particularly with relatively large or comparatively heavy items such as potatoes or other produce. The weight and impact of these types of items as they were introduced during bag filling was received directly onto the seam joining the bag wall sheets together. Problems with breakage or rupture of the seams have occurred because of this. Further, bag filling operations have been disrupted and products for filling the bags spilled or wasted.